U.S. banking giant Wells Fargo (NYSE: WFC) finds itself at the top of most investors' lists when it comes to picking the highest quality operator among the megabanks.

Skeptics don't have to look any further than the bank's valuation -- investors have given Wells Fargo's stock a much higher valuation than troubled competitors Bank of America (NYSE: BAC) and Citigroup (NYSE: C), and a notable edge over JPMorgan (NYSE: JPM) as well. While this isn't a fool-proof sign that Wells Fargo is a better bank than the others, it's certainly a sign that investors believe that.

But what exactly is it that has investors flocking to Wells Fargo? The three points below have a lot to do with it.

1. A clear strategy in view
Call me old fashioned, but I believe that the most long-term successful companies are those that are focused on offering a product or service to customers that they'll value and continue to come back for. Right at the opening of its annual 10-K filing, Wells Fargo makes clear what it's all about:

Our vision is to satisfy all our customers' financial needs, help them succeed financially, be recognized as the premier financial services company in our markets and be one of America's great companies.

This is different than what we get from the other big banks. Here's what I was able to find near the beginning of Citi's 10-K:

During 2011, Citigroup remained focused on executing its strategy of growth through increasing the returns on and investments in its core businesses of Citicorp -- Global Consumer Banking and Institutional Clients Group -- while continuing to reduce the assets and businesses within Citi Holdings in an economically rational manner.

And the closest that I could find for JPMorgan was:

The Firm is a leader in investment banking, financial services for consumers and small businesses, commercial banking, financial transaction processing, asset management and private equity. Under the J.P. Morgan and Chase brands, the Firm serves millions of customers in the U.S. and many of the world's most prominent corporate, institutional and government clients.

Wells Fargo comes off as a more focused and cohesive organization with bigger, broader goals in its crosshairs. This likely has a lot to do with the overall success of the bank.

2. Safety
In a recent presentation, Wells Fargo emphasized its safety over its main big-bank competitors. The bank highlighted that its credit charge-offs, trading assets, and value at risk -- a measure of how much financial risk is taken on a day-to-day basis -- are all lower than JPMorgan's, B of A's, and Citi's. It also noted that its ratio of deposits to total liabilities -- a measure of balance sheet stability and liquidity -- is higher than those of the other three banking giants.

This should be attractive to investors that are still spooked by the financial crisis. However, it's notable that this can be a double-edged sword since taking less risk can also limit returns. If the market continues to recover and the other banks maintain riskier profiles than Wells Fargo, they could start generating enviable profits.

While that should certainly be a consideration, profits are only as good as a bank's ability to hold onto them. Between 2008 and 2009, Citigroup swallowed tens of billions of dollars in losses. Wells Fargo didn't have a single unprofitable year during the downturn.

3. A big stamp of approval
Apologies to those tired of hearing about Warren Buffett, but we just can't overlook the fact that one of the greatest investors of our time is a huge fan of Wells Fargo. Buffett is so high on Wells Fargo's business that back in 2009, he quipped that, "If I had to put all of my net worth into stock, that would be the stock."

Today, Buffett's company, Berkshire Hathaway (NYSE: BRK-B) owns $14 billion in Wells Fargo stock, a stake that equates to nearly 8% of the bank.

Buffett's enthusiasm alone shouldn't be the reason you buy Wells Fargo's stock. After all, Buffett has made his share of mistakes and if he ever changes his view on Wells Fargo, you're probably not going to be the first call he makes. The thumbs-up that Wells Fargo gets from Buffett can, however, be a good reason to put it on your short list of companies to take a closer look at.

The right pick for you?
For those investors looking for a great, well-run bank, this Buffett favorite may fit the bill. That's exactly why I've given Wells Fargo a thumbs-up in my Motley Fool CAPS portfolio.

For the investors that are less concerned with chasing the highest-quality bank and are willing to take a chance on a cheaper pick, Bank of America may be more enticing. To get a better idea of whether you should bite on the low valuation on B of A's stock, be sure to click here and check out The Motley Fool's special report on Bank of America.